how to write a step reader?

I need to develop a tool to compare geometric structure of point cloud from scanned objects with their CAD model. The CAD model is stored in step file. So how could I extract geometric information from step file? I am totally new for CAD. Could you give me some suggestion or tell me any library which can do this job. Any help would be appreciated. Thanks in advance.
which format of STEP is it?? AP204,216,242 or any other and which cad tool are u using?? i guess NX
Last edited on
The Point Cloud Library (or PCL) may be of help to you...
http://pointclouds.org/
Thanks for your suggestion. The step file is generated from CATIA. I read a little bit about it, the format of step is P21.
Hi, I checked, the format of step should be AP203
Then its quite simple, catia has option for import/export of step file, u just need to invoke that option programmatically, and then compare it with existing geometries.
In case u dont want to import the geometry, there are third party API's to parse the step file and extract info, i have worked only AP242 , i dont know much abt others.

u can post ur doubts in solid works forum, people will surely help u :)
https://forum.solidworks.com/thread/12816
thanks for your quick reply. I know catia can import and export .stp format file. But my task is for a product, to compare point cloud from scanning with its CAD model. I have some background to detect objects from point cloud, but I know nothing about CAD model. I need to write C++ program to compare it, so I need to extract geometrical information from step file generated from CATIA. So I have I could find some libraries which can do this job. Thanks again, I will try to ask in solid works forum.
Topic archived. No new replies allowed.